Brake actuating mechanism



Aug. 11, 1936.

J. W. vWHITE BRAKE ACTUATING MEGHANI SM Filed July 50,

ATTORNEYS PatentedAug.' 11, 1936 UNITED STATES BRAKE ACTUATHVG MECHANISM John William White, Detroit, Mich" assignor, by

mesne assignments, to General Motors Corporation, a corporation of Delaware Application July 30, 1934, Serial No. 737,651

6Claims.

The invention relates to brake actuating mechanism and refers more particularly to the hydraulic type of brake actuating mechanism.

The invention has for one of its objects to provide an improved connection between the piston of the master cylinder and the brake lever. Another object is to so form the connection that it may be adjusted to properly position the brake lever in its ofi position. A further object is it to provide means for holding from rotation about its axis the rod which is connected to the piston so that dage to either the connection between the rod; and the piston or the sealing boot be tween the rod and the c is avoided.

is These and other objects of the invention become apparent from the follo description,

taken in connection with the accompo, no

wing, in which Figure l is o side elevation of a brake actuatgo ing mesh on in of my invention.

' Figure 2 is a plan view thereof;

Figure 3 is a cross section on the e 3-8 of? 25 The brake i. .w lent the hydraulic type and comprises the c i having the mr cylinder 2 and the reservoir 3. The outlet 4% oi the or cylinder isconnected hr the usual pipe to the brake actuators or wheel to cylinders. 5 is e piston slidable within the master cylinder and t is the stop in the nature of e split ring secured in the casing and engageable with the piston to t its retractile movement. The master cylinder 2 is adapted to communicate 35 with the reservoir 3 through the restricted port "i when the piston is in its retracted position.

8 is the brake lever which, as shown, is the brake pedal pivotally connected to the chassis trame of the motor vehicle by the horizontal 40 pin 6 end it is the retracting coil spring connected at one end to the chassis frame and at the other end to the brake lever below its pivot to hold the latter in its normal or oil position. This brake lever is positively connected to the 4 piston 5 so that the retracting spring also serves-- to retract the piston. The connection between the brake lever and the piston comprises the rod 8 i which is pivotally connected at one end by the horizontal pin it to the piston. The con- 50 nection also comprises the clevis it which is pivotally connected at one end by the horizontal pin it to the brake lever above its pivot. The rod and the clevis are connected to each other.

' 'ln operatiomit will be seen that the brake lever 55 swingsthroughaverticalpathasdoesalsothe this brake lever is in its ofi position and the m piston 5 is in its retracted position and engaging the stop d, the rod ii and the clevis it are adj f ably connected to each other. At the same time they are connected together in a manner which prevents the rod it from rotat about its axis so that do if of the pivot pin it or the boot is or tooth is avoided. In detail, the red [It the end portion it which extends into e het formed by the tongues ii into a? with and at one end of the clevis it. 'lhese tongues practically form 2. tapered ter face of circular cross section, and are preferably formed by lotu slotting the end of the clevis and furthermore these tongues are topc and have increasing thicmess from the free ends toward their other ends. The outer faces or peripheries of these tongues are aded. ilhe end portion it of the rod ii is round and externally threaded and the threads or serrations it are hardened i8 is a pin extending thro the end portion it and preferably having a drive fit therewith, the ion of the pin being such m its end portions extend into the slots it between the tongues it so that the rod H is held from rotation about its axis relative to the clevis is. is is e nut threaded upon the end portion 66 and abutting the ends of the tongue ii, and 20 is a second nut having tapered internal threads corresponding to the taper of the external threads of the tongues ii. The arrangement is such that by threading the nut 29 upon the tongues, the tongues are forced radially inwardly to firmly engage the end portion It. Since the external threads upon this end portion are hardened, they bite into the inner faces of the tongues andvserve to more firmly connect the rod II and the clevis l3.

In assembling, with the piston 5 in its retracted position and in engagement with the stop I and the brake lever in its forward position, the nut 20 istightened partially upon the tongues l'l and then the nut i9 is turned in a dlrection'to force the rod ll out of the tongues. This serves to swing the brake lever rearwardly and the turning of the nut I9 is carried on until the desired position of the brake lever relative to the foot boards is secured, after which the nut 20 is firmly tightened upon the tongues H to compel the serrations upon the end portion [6 to bite into the tongues, at which time the parts are all effectively connected together.

What I claim as my invention is:

1. In brake actuating mechanism, the combination with a master cylinder and a piston therewithin and a brake lever, of a rod operatively connected to said piston, a member connected to said brake lever, means engaging both rod and member holding said rod and member from rotation, and means for adjustably securing said rod and member together.

2. In brake actuating mechanism, the combination with a master cylinder and a piston there within and a brake lever, of a rod, a pin pivotally connecting said rod to said piston, a member, a pin pivotally connecting said member to said brake lever, means engaging both rod and member for maintaining said rod and member in predetermined angular relation to hold said pins substantially parallel, and means for adjustably securing said rod and member together.

3. In brake actuating mechanism, the combination with a master cylinder, a piston therewithin and a stop for limiting the retractile movement of said piston and a brake lever pivotally mounted to swing through a vertical path, of a rod operatively connected to said piston, a member connected to said brake lever, means engaging both rod and member holding said rod and member from rotation, and means for ad- 'justably securing said rod and member together to secure proper positioning of said brake lever when said piston engages said stop.

4. In brake actuating mechanism, the combination with a master cylinder, a piston therewithin and a stop for limiting the retractile movement of said piston, a brake pedal pivotally connected to swing through a vertical path, and a spring for normally maintaining said brake pedal in ofi position, of a rod pivotally connected to said piston to swing through a vertical path, said rod having an end portion provided with hardened serrations on its face, a clevis pivotally connected to said brake lever and provided with externally threaded tongue portions forming a socket for receiving said serrated portion of said rod, means upon said serrated portion of said rod extending between said tongue portions for holding said rod and clevis from relative rotation, and means threaded upon said tongue portions for clamping the same upon said serrated portion of said rod.

5. In brake actuating mechanism, the combination with a master cylinder and a piston therewithin anda brake lever, of a rod operatively connected to said piston and having an end portion provided with serrations on its face, a clevis connected to said brake lever and having tapered tongues providing a socket for receiving said end portion, said tongues being externally threaded, a pin upon said end portion extending between said tongues, an adjusting nut threaded upon said end portion and abutting said tongues, and a nut threaded upon said tongues for clamping the same upon said end portion.

6. In brake actuating mechanism, thecombination of a casing having a master cylinder, 9. piston within said master cylinder, a rod pivotal- 1y connected to said piston, a sealing boot encircling and secured to said rod and having sealing engagement therewith and with said casing, a pivotal brake pedal, a clevis pivotally connected to said brake pedal, cooperating means engaging said rod and clevis for holding the same from relative rotation, and means for adjustably securing sm'd rod and clevis together.

JOHN WILLIAM WHI'I'E. 

